#include<stdio.h>
int main(int argc, char const *argv[])
{
    int a=21,i;
    printf("Game begin:\n");
    while (a>0)
    {
        do
        {
            printf("How many sticks do you wish to take (1~%d)?",a>4?4:a);
            scanf("%d",&i);
        } while (i>4||i<1||i>a);
        if(a-i>0)
            printf("%d sticks left in the pile. \n",a-i);
        if((a-i)<=0){
            printf("You have taken the last sticks. \n");
            printf("****You lose! \nGame Over.\n");
            break;
    }
    else
     printf("Computer take %d sticks.\n",5-i);
     a-=5;
     printf("%d sticks left in the pile.\n",a);
    }
    return 0;
}
